Python 自定义两个列表映射

Question

我有一个对象 ID 的映射:

mapping = {'id-1':'id-10', 'id-2':'id-14', 'id-3':'id-19'}

还有两个包含对象的列表，id是对象的属性，例如object_id1.id = 'id-1'。

list1 = [object_id1, object_id3, object_id4, object_id5]
list2 = [object_id19, object_id11, object_id14, object_id10]

我想要一个包含一组相关对象的列表。如

output = [(object_id1, object_id10), (object_id2, object_id14),(object_id3, object_id19)]

是否可以在一个 for 循环中完成它？

Answer 1

您无法在单个 for 循环中执行此操作，但可以在两个(非嵌套)循环中执行此操作:

>>> mapping = {'id-1': 'id-10', 'id-2': 'id-14', 'id-3': 'id-19'}
>>> list1 = [object_id1, object_id3, object_id4, object_id5]
>>> list2 = [object_id19, object_id11, object_id14, object_id10]

构造一个查找字典，用于在 list2 中按 id 查找项目:

>>> lookup_dict = {item.id: item for item in list2}

那么你可以简单地做:

>>> output = [(item, lookup_dict[mapping[item.id]]) for item in list1 if mapping[item.id] in lookup_dict]